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https://issues.apache.org/jira/browse/ASTERIXDB-1556?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=15623089#comment-15623089
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Michael J. Carey commented on ASTERIXDB-1556:
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Very cool! Thanks for checking that carefully - +1 from on merging from
a perf-was-verified perspective. It would also be nice to quickly
compare (independent of this change) the perf of hash-based vs.
sort-based aggregation on the two (low-cardinality and high-cardinality)
cases and have a quick look at the numbers to make sure that all still
works as expected in the new world of aggregation. (Which I guess will
verify that it was working as expected in the N-1st world of
aggregation, since the performance is now known to be the same before
and after, when memory settings are set appropriately.)
Thx,
Mike
> Hash Table used by External hash group-by doesn't conform to the budget.
> ------------------------------------------------------------------------
>
> Key: ASTERIXDB-1556
> URL: https://issues.apache.org/jira/browse/ASTERIXDB-1556
> Project: Apache AsterixDB
> Issue Type: Bug
> Reporter: Taewoo Kim
> Assignee: Taewoo Kim
> Priority: Critical
> Labels: soon
> Attachments: 2wayjoin.pdf, 2wayjoin.rtf, 2wayjoinplan.rtf,
> 3wayjoin.pdf, 3wayjoin.rtf, 3wayjoinplan.rtf
>
>
> When we enable prefix-based fuzzy-join and apply the multi-way fuzzy-join ( >
> 2), the system generates an out-of-memory exception.
> Since a fuzzy-join is created using 30-40 lines of AQL codes and this AQL is
> translated into massive number of operators (more than 200 operators in the
> plan for a 3-way fuzzy join), it could generate out-of-memory exception.
> /// Update: as the discussion goes, we found that hash table in the external
> hash group by doesn't conform to the frame limit. So, an out of memory
> exception happens during the execution of an external hash group by operator.
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